1. Field of the Invention
The present invention relates to a system for stock rotation of liquids, such as soft drink syrups, contained in large non-pressurized containers such as 55 gallon drums. More specifically, the present invention relates to an automatic changeover device for automatically switching between a primary 55 gallon drum and a secondary 55 gallon drum in response to an empty condition of the primary 55 gallon drum without the interruption of the syrup supply by air in the dispensing line.
2. Description of the Prior Art
Heretofore the stock rotation or changing of liquid containers or drums such as milk, soft drink syrups or chemicals, has been accomplished by manual methods. When a container became empty, the pump system was not supplied with liquid until the packages could be manually changed. This caused unavoidable, unexpected and inconvenient delays in the dispensing operation. To provide for larger reserves many prior art systems connected packages in a parallel arrangement. This does not provide for the necessary stock rotation required by many perishable food items such as milk and soft drink syrups. Additionally, rigid types of containers having inlet and outlet openings are often connected in series. This connection does not provide complete rotation of liquid products since mixing occurs. In both series and parallel connections, a problem exists in that when all containers are empty the dispensing system must be shut down in order to replenish the supplies.
Automatic changeover devices for non-viscous liquids disposed in open or vented containers have been known in the art. However, a problem with these prior art changeover devices has been the accumulation of air at changeover in the supply lines. For large containers, such as 55 gallon drums, the amount of air in the supply lines upon changeover would be excessively large and would result in the deterioration of the quality of the dispensed product.